Document name Path Operator Plan

1 Document name path Operator plan Category ( ) Regional reliability standard ( ) Regional criteria ( ) Policy ( ) Guideline ( X ) Report or other ( ) Charter Document date January 17, 2013 Adopted/approved by Date adopted/approved Custodian (entity responsible for maintenance and upkeep) WECC Staff Stored/filed Physical location: Web URL: Previous name /number (if any) Status ( ) in effect ( ) usable, minor formatting/editing required ( ) modification needed ( ) superseded by _____ ( ) other _____ ( ) obsolete/archived) W E S T E R N E L E C T R I C I T Y C O O R D I N A T I N G C O U N C I L W W W.

2 W E C C . B I Z 1 5 5 N O R T H 4 0 0 W E S T S U I T E 2 0 0 S A L T L A K E C I T Y U T A H 8 4 1 0 3-1 1 1 4 P H 8 0 1 . 5 8 2 . 0 3 5 3 White Paper path Operator plan By WECC Staff Western Electricity Coordinating Council January 17, 2013 January 17, 2013 3 W E S T E R N E L E C T R I C I T Y C O O R D I N A T I N G C O U N C I L W W W . W E C C . B I Z 1 5 5 N O R T H 4 0 0 W E S T S U I T E 2 0 0 S A L T L A K E C I T Y U T A H 8 4 1 0 3-1 1 1 4 P H 8 0 1.

3 5 8 2 . 0 3 5 3 White Paper: path Operator plan Executive Summary Issues exist throughout the Interconnection with the roles and responsibilities of various entities with regard to Paths. These issues have been highlighted by multiple events in the past. Arizona Public Service (APS) has been leading discussions of the affected entities1 from the September 8, 2011 outage as a starting point for agreement on the issues. A whitepaper is expected out of that group at the end of January 2013. Problem Statement A path is a set of parallel transmission elements for which scheduled and actual flow can be monitored for reliability purposes.

4 Paths are also often called cutplanes. In many cases, the System Operating Limit (SOL) for the path is lower than the sum of the SOLs for the individual components, so it is possible for the path to exceed its SOL without any individual facility rating exceeding its limit. Roles and responsibilities for Paths can be complicated, as there may be multiple owners, operators, and scheduling entities for portions of the Paths. Although this problem has been highlighted by WECC Transfer path 49 (East of the Colorado River), Staff estimates that this problem exists on as many as 10 Paths within the Interconnection.

5 One of the key problems identified by path Operators with the current structure is that the path Operator is not defined in the NERC Functional Model, and as such does not have specific authority defined in mandatory standards to direct other Transmission Operators to take action. Furthermore, some path Operators have limited visibility of schedules flowing across the path . Although contractual arrangements have been suggested to some path Operators, they have indicated that the counterparties have no incentive to enter into such contracts.

6 1 Entities affected by the September 8, 2011 Pacific Southwest outage include San Diego Gas and Electric (SDGE), Imperial Irrigation District (IID), Arizona Public Service (APS), Western Area Power Adminstration Lower Colorado (WALC), Southern California Edison (SCE), Comision Federal de Electricidad (CFE) and California Independent System Operator (CISO). The majority of discussions regarding path Operator roles and responsibilities have taken place amongst entities impacted by WECC Transfer path 49 (East of Colorado River) operations, namely, APS, CFE CISO, SDGE, WALC and the WECC RC.

7 January 17, 2013 4 W E S T E R N E L E C T R I C I T Y C O O R D I N A T I N G C O U N C I L W W W . W E C C . B I Z 1 5 5 N O R T H 4 0 0 W E S T S U I T E 2 0 0 S A L T L A K E C I T Y U T A H 8 4 1 0 3-1 1 1 4 P H 8 0 1 . 5 8 2 . 0 3 5 3 Background In 2008, an event occurred where path 49 exceeded its limit. The Reliability Coordinator directed APS, as the path Operator , to take action to reduce flows, up to and including shedding firm load. However, APS load was on the wrong end of the constraint to relieve the overload, and APS did not have sufficient authority to direct actions to reduce flow.

8 The outage on September 8, 2011, also raised questions about path operations in the Pacific Southwest and SOLs of facilities on those a meeting of the CEOs of the affected entities for that event, APS volunteered to lead an effort to identify the issues surrounding the path Operator issue. The first meeting to discuss path Operator issues occurred on October 19, 2012. During this meeting and two subsequent meetings, participants discussed problems associated with their individual Paths, as well as potential solutions. During the December 17, 2012 meeting, APS presented a draft whitepaper outlining the issues and history of path issues.

9 The paper was distributed for comment and is expected to be finalized during a conference call on January 28, 2013. During the December meeting, the group also discussed the potential for WECC to take a lead on discussions of potential solutions due to the Interconnection-wide effects. Proposed Project plan January 31 February 1, 2013: Joint Guidance Committee WECC Staff would introduce the path Operator issue and propose forming a cross-functional Task Force to discuss issues and develop a recommendation for a solution. Late February 2013: Task Force Meeting The path Operator Task Force, preferably including path Operators from around the Interconnection, would discuss an approach to the path Operator issue.

10 APS and the September 8 entities will be asked to present the whitepaper that they have developed. The Task Force will plan a series of educational webinars on various topics affecting path Operations. March May 2013: Educational Series The path Operator Task Force and/or WECC Staff will present a series of educational webinars on various topics including: History of Paths and the path Rating Process Flow-based methodology and differences between the Western Interconnection and Eastern Interconnection January 17, 2013 5 W E S T E R N E L E C T R I C I T Y C O O R D I N A T I N G C O U N C I L W W W.